Sophie Mott, Research intern at Hope Farm, provides the 2018 results of the butterfly and bee monitoring season.
As you may have seen in an earlier post, the extreme weather of spring and summer 2018 meant a tough year for farmers and wildlife alike, notably for our birds. Territory holdings and breeding success suffered for many species across the farm and now we can only hope to support as many birds as possible through the winter for a successful season next summer. However, the endless sunshine didn’t bring doom and gloom for everyone. For our pollinators the scorching summer sun brought great joy and a record year for us.
At Hope Farm, it’s not just our birds that we monitor to the national gold label standard. We also monitor our butterflies under the UK Butterfly Monitoring Scheme. The surveys take place every week from April to September along three transects, and this year’s butterfly index was a record high here, at an amazing 223% above the baseline index recorded in 2001 (fig. 1).
Figure 1 shows the change in UK Butterfly Monitoring Scheme index between 2001 and 2018, both nationally (yellow) and specifically at Hope Farm (green).
As the summer sun continued, it became clear that some species were really flourishing. By the end of the season we had recorded over an incredible 5000 individuals of 26 species. This included over 600 Common Blue, 46% of the total number of this species recorded on surveys since 2001. Additionally, both Brown Argus and Small Copper were at record high levels, and we had White-letter Hairstreak recorded on the farm for the first time. The prolonged heat caused a shortened flight period for Browns with lower counts than usual, but they were still relatively common. Small Tortoiseshells had a bad year, a result also seen on Butterfly Conservation’s national Big Butterfly Count.
Red admiral at Hope Farm. Image: @spinkybird
Butterflies are an indicator species for the state of the environment, they have rapid life cycles and can be particularly sensitive to environmental changes. Monitoring this taxon through the UK butterfly monitoring scheme allows us to compare our results to national fluctuations in butterfly diversity.
Bees provide many ecosystem services to the farmed and wider environment, including being extremely important pollinators. Unfortunately, in recent years their populations have drastically declined. It is important for us to show with evidence that providing flower rich areas of the farm through summer can help to restore bee diversity in the agricultural landscape.
This year was our 5th year of contributing to the Bumblebee Conservation Trust national monitoring scheme, recording bee numbers on Hope Farm and a neighbouring control farm without any wildlife-friendly conservation areas. The surveys run from April to August, on both farms, to help us see how different agricultural systems effect bee populations.
Following such a cold spring the first surveys gave us unsurprisingly low numbers on both farms. As the season turned to summer, the air around Hope Farm started vibrating with little wing beats, but the numbers on the control farm hardly changed. In the peak of summer, Hope Farm recorded the equivalent of 1 bumblebee per 17 metres of transect whereas the control farm only recorded 1 bumblebee per 344 metres of transect (fig. 2).
Figure 2 shows the abundance of bees during the survey season of 2018 both at Hope Farm (green line) and the control farm (blue line).
Now that the nights close in earlier and the frosts draw in, many of these species, like many other invertebrates, will be fading from our landscape. As the temperature continues to drop they will start to disappear, with some hunkering down underground or in nests to wait out the long winter, and dream of the glorious arrival of spring where it all starts again. Hopefully, it will be another bumper pollinator year.
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